It's Week 5, and the University of Colorado football team is undefeated.

(That's not the entire story of course. But hey, 2-0 is 2-0.)

The question facing every team outside the AP top 25 with a zero in the loss column is, are they for real? In CU's case, can the Buffs, a year after finishing 1-11, realistically win four more games and qualify for a bowl?

That last question could be answered Saturday (1 p.m., Pac-12 Network), when Colorado visits Oregon State. It's the Buffs' conference opener and it's a swing game, one of only a handful left on Colorado's schedule.

The Buffs won't be favored against many of their opponents, if any, the rest of the way. That's not to say they can't knock off a few of them. Games aren't decided by betting odds. But aside from Oregon State, Arizona, California, Utah and the to-be-announced 12th regular-season opponent (let's assume it's a California State school), which of the Buffs' remaining opponents would you bet your life savings against when they play Colorado?

Before the season, I said the Buffs would win five games, best-case scenario. I could not find a coveted sixth win on their schedule. Didn't see them beating Oregon State. Didn't see them beating Arizona State. Didn't see them beating UCLA, Washington, USC or Fresno State. Or Oregon.

As of Wednesday, however, I think they have a good shot at 3-0.

They can match up well with the Beavers. Oregon State (3-1) has been riding quarterback Sean Mannion and Brandin Cooks in the same way Colorado has ridden Connor Wood and Paul Richardson.

Running back Storm Woods won't be available for the Beavers, so their offense will be largely one-dimensional as it was last week, when Mannion attempted 55 passes against San Diego State. Oregon State won 34-30 on a late pick-six by cornerback Steven Nelson. Aside from that, the Beavers' defense has been nothing to write home about.

That unit has allowed 33.5 points per game, including that infamous 49-46 loss to Eastern Washington of the FCS, and 287 passing yards, which bodes well for Richardson. San Diego State wideout Colin Lockett carved up the Oregon State secondary for 113 receiving yards. A week earlier, Utah's Dres Anderson went for 101 yards. Even Eastern Washington had a 100-yard receiver against Oregon State, two actually.

The real challenge for Colorado will be stopping Mannion, as Buffzone's Brian Howell wrote this week. He leads the nation in passing yards (1,604) and has helped make Cooks the nation's leading receiver (639).

Although it was two weeks ago, the CU secondary got a good primer against Central Arkansas. Bears quarterback Wynrick Smothers threw 55 passes, completing 33 of those for 280 yards and two touchdowns to three interceptions.

If the Buffs can score like they can, contain Cooks and put pressure on Mannion, they just might get out of Reser Stadium with a huge win.

And maybe, just maybe, three more will follow.

In other Pac-12 football news:

- Buffzone's Brian Howell says facing San Jose State is an attractive option for Colorado, even if Buffaloes coach Mike MacIntyre doesn't like it.

- Colorado is preparing for its first road trip under MacIntyre, write Buffzone's Kyle Ringo.

- Some shameless self-promotion: Here's my Pac-12 Week 4 wrap.

- Oregon State notebook, courtesy of Kevin Hampton and Steve Gress of the Corvallis Gazzette-Times: Mannion is enjoying a hot stretch.

- The San Francisco Chronicle's Hunter Hewitt repots Cal is trying to improve its sluggish ground game.

- Oregon quarterback Marcus Mariota has a commanding lead in ESPN's Heisman straw poll.

- The rich get richer: UCLA running back Damien Thigpen is expected to return from injury for the Bruins' next game, an Oct. 3 road test against Utah, according to Chris Foster of the Los Angeles Times.

- Huskies offensive line has regained the trust of quarterback Keith Price, story by Percy Allen of The Seattle Times.

- Also from The Seattle Times, the Cougars seems ready to play anyone, anywhere. Washington State plays Stanford at CenturyLink Field on Saturday.

- The L.A. Times' Gary Klein explains why explains why USC's offense will get better.

- The Tucson Citizen's Anthony Gimino introduces Arizona's 'short but mighty' freshman receivers.

- More injury news for the Cardinal: All-American guard David Yankey won't play Saturday against Washington State, writes Jon Wilner of the San Jose Mercury News.

- The Salt Lake Tribune's Lya Wodraska says Utah needs to improve on third down

- Redshirt freshman linebacker Salamo Fiso has earned playing time for Arizona State, according to Doug Haller of azcentral.com.

Follow Scott on Twitter @SJAdams